I am working with a PSoc3 chip. First time using the PSoC, and I am wondering can I send a sine wave into an analog input to a low pass filter inside the PSoC? Since the PSoC is running at 3.3vdc the sine wave will canter on 1.5vdc and swing approximately 1vp/p.

Is this allowable or is the analog input DC level only? Also, if the answer is YES that I can send a sinewave into the device, can I take th eoutput of my PWM, and send it through an internal integrator and output a sine wave?

Yes, you can send in a sine wave to the PSoC3 - its inputs are perfectly capable to handle AC inputs (up to several MHz, depending on the voltage levels). But you cannot go below ground or above Vdda with your signal - but your proposed signal would be fine even with 3.3V Vdda.

I think there is no internal integrator, but you should be able to build one by yourself using the inernal OpAmps and some external capacitors / resistors. Or you go experimental and digitize the signal and feed it into the digital filter...